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Extracting numbers from vectors of strings
...ion is an indirect way of getting to the solution. If you want to retrieve all the numbers, I recommend gregexpr:
matches <- regmatches(years, gregexpr("[[:digit:]]+", years))
as.numeric(unlist(matches))
If you have multiple matches in a string, this will get all of them. If you're only intere...
Add more than one parameter in Twig path
...n pass as many arguments as you want, separating them by commas:
{{ path('_files_manage', {project: project.id, user: user.id}) }}
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What are paramorphisms?
...foldr c n xs)
para c n [] = n
foldr c n [] = n
Some people call paramorphisms "primitive recursion" by contrast with catamorphisms (foldr) being "iteration".
Where foldr's two parameters are given a recursively computed value for each recursive subobject of the input data (here, that...
Mutex example / tutorial? [closed]
... The first person to catch the door-handle of the booth, is the one who is allowed to use the phone. He has to keep holding on to the handle of the door as long as he uses the phone, otherwise someone else will catch hold of the handle, throw him out and talk to his wife :) There's no queue system a...
What are the use(s) for tags in Go?
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A tag for a field allows you to attach meta-information to the field which can be acquired using reflection. Usually it is used to provide transformation info on how a struct field is encoded to or decoded from another format (or stored/retrie...
Detect backspace in empty UITextField
...yTextField
- (void)deleteBackward {
[super deleteBackward];
if ([_myDelegate respondsToSelector:@selector(textFieldDidDelete)]){
[_myDelegate textFieldDidDelete];
}
}
@end
Now simply add MyTextFieldDelegate to your UIViewController and set your UITextFields myDelegate to sel...
Create an array with random values
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var random_array = new Array(40).fill().map((a, i) => a = i).sort(() => Math.random() - 0.5); I think this does the same as above
– Jamie337nichols
Sep 16 '19 at 18:47
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Compelling examples of custom C++ allocators?
What are some really good reasons to ditch std::allocator in favor of a custom solution? Have you run across any situations where it was absolutely necessary for correctness, performance, scalability, etc? Any really clever examples?
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Left align two graph edges (ggplot)
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Using cowplot package:
A <- ggplot(CO2, aes(x=Plant)) + geom_bar() +coord_flip()
B <- ggplot(CO2, aes(x=Type)) + geom_bar() +coord_flip()
library(cowplot)
plot_grid(A, B, ncol=1, align="v")
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How to use string.replace() in python 3.x
... The "re" (regular expression) module has alternatives for (some? all?) deprecated string functions. In this case, re.sub().
– ToolmakerSteve
Dec 13 '13 at 22:19
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